Nice Nano Tank! Looks really promising. I am really interested in how your carpet plants will do with the original lighting of your tank.
I have found in my 20l tank that 11W is not enough for my Hemianthus Micranthemoides and HC carpet, the HM is known to grow leggy when not receiving enough light. Plant health and carpeting has improved considerably when I installed one additional 6W T5 lamp just above the FG carpet. Later I added a second 6W tube to the back too.